Sökning: "perovskites"

Visar resultat 1 - 5 av 50 avhandlingar innehållade ordet perovskites.

  1. 1. Neutron spectroscopy studies of vibrational and diffusional dynamics in organometal halide and oxyhydride perovskites

    Författare :Rasmus Lavén; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; Metal halide perovskites; perovskites; phonons; quasielastic neutron scattering; inelastic neutron scattering; oxyhydrides; hydrogen dynamics.; diffusion;

    Sammanfattning : This thesis deals with inelastic and quasielastic neutron scattering studies on the dynamical properties of the organometal halide perovskite system MA1-xFAxPbI3 (MA = methylammonium; FA = formamidinium) and of the layered perovskite-type oxyhydride SrVO2H. These materials systems are of high interest for their excellent photovoltaic performance (MA1-xFAxPbI3) and hydride-ion conductivity (SrVO2H) and concomitant promise for various technological devices; however, the local structure and dynamics underpinning these materials properties remain unclear. LÄS MER

  2. 2. Vibrational proton dynamics in hydrated perovskites and alkali thio-hydroxogermanates

    Författare :Maths Karlsson; Chalmers University of Technology; []
    Nyckelord :fuel cell; proton conduction; perovskites; proton dynamics; thio-hydroxogermanates; vibrational spectroscopy;

    Sammanfattning : .... LÄS MER

  3. 3. Solid state proton conductors: hydrated perovskites and hydrated alkali thio-hydroxogermanates

    Författare :Maths Karlsson; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; neutron scattering; vibrational spectroscopy; alkali thio-hydroxogermanates; Proton conductors; fuel cells.; perovskites;

    Sammanfattning : This thesis concerns experimental studies of hydrated perovskites and hydrated alkali thio-hydroxogermanates, two classes of solid state proton conductors which are promising to be used as electrolytes in future intermediate temperature (200-500°C) fuel cells.This is an attractive temperature range for many applications but for which today's available electrolytes do not show satisfactory performance. LÄS MER

  4. 4. Functional Oxide Materials exhibiting Ionic Conductivity for Future Energy Conversion Needs

    Författare :FRANCIS GACHAO KINYANJUI; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; neutron diffraction; perovskites; oxygen deficient perovskites; BaSnO3; Rietveld refinements; BaZrO3; in-situ cells; proton conduction; deuteron position; Ba3In2ZrO8;

    Sammanfattning : Fuel cells are electrochemical devices that transform the chemical energy in hydrogen and oxygen into electrical energy at high efficiencies and produce only water vapour emissions. Materials with the perovskite or fluorite structure types are commonly employed as the ion conducting ceramic electrolyte membranes in intermediate and high temperature fuel cells. LÄS MER

  5. 5. The life and death of perovskites : Interfacial function and degradation of lead halide perovskites studied by photoelectron spectroscopy

    Författare :Sebastian Svanström; Ute B Cappel; Håkan Rensmo; Erik Johansson; Selina Olthof; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; lead halide perovskite solar cells; interfacial degradation; heterojunction interfaces; photoelectron spectroscopy; operando; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : Lead halide perovskite solar cells are a promising new technology which could soon see widespread commercial application but is partly held back by poor long-term stability. In this thesis, photoelectron spectroscopy (PES) is used to study the dynamical processes at the surface or interfaces of lead halide perovskite materials. LÄS MER